Reproducing mechanism



aEPRoDucim uzcrmusu Filed March 14, 192s: 4 Sheets-Sheet 2 C. KREBSREPBODUCING MECHANISM May 27, 1930.

4 Sheets-Sheet .3

Filed March 14, 1929 c. KREBs v REPRODUC ING HECHANI SM May 27, 1930.

Filed Match 14, 1929 4 Sheets-Shget 4 Patented May 27, 1930 UNITEDSTATES CARLOS KREBS BOSTON, MASSAGH'U'SETTS REPRODUGING MECHANISMApplication filed March 14, 1929, Serial No This invention relates to animprovement in reproducing mechanism of the type shown in my copendingapplication Serial No. 288,023, filed June 25, 1928, and which may beemployed in various machines, as for example in the torch cuttingmachine disclosed in that application, and which includes means forcontrolling the reproductive movements of one or more tools or otherelements used in cutting, welding, profiling and other ma- 'chineryhaving drives which are either directly or indirectly controlled.

The use of cutting machines of this character has increased greatlywithin the past few years for the purpose of producing standard partswhich must be replaced pe-' riodically, such as locomotive parts, or forproducing in large quantity parts to be used for the construction of newmachinery. The template with which the tracer coacts is supposed toserve as a long-lasting pattern by the use of which parts are reproducedcorrectly so long as the pattern is serviceable,

sential that the reproductions be always the same, and it isaccordinglyv necessary that the I specificfeatures of the cuttingmachines must be such that the parts are reproduced correctly andpermanently. Moreover, it is now .the practice in electrical companiesto produce smaller motors and generators in mass I production, usingsteel elements instead of castings. One factory of this type now turns 5out 800 motor frames per week, each motor being provided with four legs,and those legs must be so formed that they can be fitted to the frameswithout further machining, and hence it is necessary that the cutting:ma .chines reproduce permanently correct parts 347,065, and, in GermanyJanuary 25", 1929.

erator.

In order that a cuttingmachine be formed to operate in the accuratemanner above mentioned, three essential features must be provided:First, the tracer and cutting torch must be mounted upon a suspensionsystem and be freely movable thereover in any or all directions in ahorizontal plane; second, the

tracer and torch must be so mounted upon the suspension system thatthey, at all times,

work in a vertical, plane; third, the mechanism by which the movement istransmitted from the tracer to the torch must compel the torch to followexactly the path'prescribed by the tracer.

Obviously all these points are fundamen tally interdependent and if inany of these features the machine is not properly designed, accuratereproduction can not be relied upon. The suspension system for thetracer and the torch must be of a kind that can not possibly get out ofthe exact horizontal plane and must be ofsubstantial and rigidconstruction permanently unaffected by any moving weights or strains. Ifthe suspension system does not remain in the horizontal plane at alltimes, it obviously follows that the tracer and torch mounted thereoncan not always work in the vertical position, and if the tracer andtorch are not so constructed as to work in a vertical'plane, then, evenif the suspension system therefor were perfectly designed, the result ofthe o eration of the machine will be unreliable." 11 other words, boththe support and the tracer and torches must be so designed. that theykeep within their respective planes permanently without any possibilityof being shift-- ed therefrom, either by reason of any faultyconstruction, or by reason of the changing of the weights and strainswhich' take during the operation of the machine.

In order thattlie relative movement be properly transmitted between thetracer and the'torch, the means for so doingmust be sensitive, engaginginstantly and forcibly without the possibility of ever developing anylost motion. Obviously this transmisplace sion means can not be a partof the supporting mechanism because the continuous shifting of thestrains would destroy its value. In other words,the transmission meansmust transmit movement and can not be used for any other purpose.-

Many designs of cutting machines have been developed, but it'has beenfound that they do, not comply with the three requirements above given.If the suspension system forthe mechanism is su ported at one end only,it necessarily must ollow that the continual shifting of the weightsduring the operation of the machine will have a'tendency to move thesuspension system out of the exact horizontal plane which it occupiedwhen the machine'was new. Another objec tion to these machines 'is thefact that in' vman part as a support for the tracer and torch. I 1

The machine which is here shown, for the purpose of illustration,embodies a torch cut. ting machine in which the movement of a pluralityof torches is controlled by and each torch reproduces the movement of atracer which is guided by. a suitably formed pattern or template hasbeen developed for the purpose of complying with each of the threerequirements. T us, the suspension system is supported at its-center andthe tracer and torch mechanisms are so arranged relative to this centersupport that they at all times balance each other and no undue strain isapplied tothe'support at any time during the operation of the machine.Furthermore, the tracer and torches are freely movable vertically and inexact parallelism, and

finally, the transmission means functions" solely for that purposeand'has no load supporting function 'at any time. Therefore,

the torches will cut from the material upon which they work a pluralityof articles which correspond in every particular to thepattern ortemplate.

The primary object of; this invention is to provide a reproducingmechanism so constructed that a plurality. of articles may besimultaneously made by the operation of tools actuated by a singlepattern or template controlled element.

Another object of this invention is to provide a repr'oducin mechanismembodying a tracer wheel guide by a template upon which it rests, and'means carried by the tracer wheel support for engaging the template toinsure the movementof the wheel'at all times in conformance with thecontour thereof.

A further object ofthis invention is to provide in areproducingmechanism transmission meanswhich operate in'a horizontalplane to transmit motion from the tracer mechanism to the torchmechanism.

Other objectsjof this invention reside in the details of constructionhereinafter set forth as willbe apparent to one skilledin the cases thetransmission ,means acts. who y or in art from a consideration of thefollowing specification taken in connection with .the

drawings which form a part thereof, and in which: 7

Fig. 1 is an elevation of a reproducing mechanism embodying thisinvention;

Fig. 2 is a plan view thereof illustrating primarily the suspension andtransmission means; 0

Fig. 3 is a sectional view on a larger scale ofthe tracer; V 3

Fig. 4 is a side elevation on a similar scale of the lower portion ofthe tracer; and

Figs. 5 and 6 are sectional detail views illustrating portions of thetransmission means.

-The embodiment set forth the drawings and described-in detail in thespecification was selected as illustrative and not as limitative, isbeing understood that other. embodl:

ments can be made in which the. subject matter of rated.

Y Referring particularly to Figs. 1 and 2 of the drawings, it will benoted that the reprothis invention maybe incorpoducing mechanismincludes a susupension' system here shown ascomprising a pair ofplatforms 10, each'of which is provided with a centrally locatedpedestal 11 by which the platform' is rotatably supported in ahorizontal plane. Suitably formed pairs of carriages 12 and 13respectively support the tracer and torch mechanism, the movement bar 17carried by posts 18 in the carriages.

Thus each pair of carriages moves as a unit.

Each pedestal 11 comprises a fixedcentral column 20 mounted on a base 21and provided with a capital 22 upon which the platform 7 10 rests. Thebase 21 may support both pedestals and be mounted upon parallel tracks23 suitably supported upon a standard'24, I

or there may be separate bases21 suitably joined to move as a unit overthe tracks 23. In the base 21 are mounted one or more axles 25 providedwith wheels 26 which engage the tracks 23. One pedestal 11 also may beprovided with a motor 27, a suitably formed gear box 28, a shaft 29, anda worm and gear assembly 30, whereby one of the shafts 25 is rotated.The operation of the motor by this construction causes the base 21 andthe pedestals 11 andall the parts carried thereby to reciprocate overthe track 23. Each capital 22 secured to its platform is mountedupon thecolumn by antifriction means (not shown) sothat it can rotate freelythereon about the vertical axis 31, thus permitting it, together withits plat- Each of the carriages. 12. and 13 comprises a frame 46 whichis supported by a pluralityof rollers 47, which rollers rest upon andare guided by the tracks 45. T

e tracer mechanism includes a tracer 50 supported upon the cross beam 15which 'is connected to the carriages 12 in such a manner that the latterare free to oscillate relative to the ends of the beam. This may beattained in any desired manner, as for example, securingthe posts bysuitable ball and thrust bearingsto the ends of the beam, so that thebeam can turn easily thereon when required during the operation of themachine.

In the center of the beam15, preferably midway between its ends, is anaperture 51 through which passes a sleeve 52 depending from a plate ordisk 53 supported upon the beam l5 as by legs 54, and secured thereto.

inanysuitabl'e manner.

The tracer is particularly shown in Figs. 3 and 4 of the drawings on alarge scale.

Supported upon the plate or disk 53 by antifriction bearings is aturntable 56 which carries-a motor 57 by means of uprights 58. Rotatablymounted 'in bosses 60 formed on the uprights 58 is a shaft 61 which isactuated through a worm and gear assembly 62 by the motor 57. Mounted torotate upon the turntable 56 between the uprights 58 are gear wheels 63which are driven from the shaft 61 by intermeshing bevel gears 64. Theturntable 56 has a central opening 65 within which a floating guide 66preferably in the form of a tube extends. Mounted at the lower end ofthe tube 66 is a block 67 provided at its lower end with arms 68 whichsupport a wheel shaft 69. Mounted upon the shaft 69 between the arms 68is a wheel 70 which is driven by the motor 57 through the gears 63. Thegears 63 mesh with spur gears 71 mounted upon the upper ends of shafts72 which extend through the tube 66 and block 67 terminating between thearms 68. The lower ends of the shafts 72 are provided with beveled gears74 which mesh with gear teeth 75 formed on the wheel 70. The wheel 70 isthus positively driven from the motor 57 by gearing which engages bothsides of the wheel,'thus equalizing the pressure thereon and preventingthe application of any undue strain against one side thereof.

The template 36 comprises a metal strip 76 which is bent in any suitableform and riveted to-a supportingplate. The wheel.70 includes a centralannular flange 77 which rests upon the upper face of the strip 7 6. Inorder to hold the wheel in this position upon the strip, there areprovided rollers 80 which rest against the sides of the strip. Theserollers are vertically supported in levers 81 pivoted upon rods 82carried by the arms 68. One or both of the levers 81 may be providedwith an extension 83 which engages bracket 84 carried by the block 67.The bracket 84 is provided with a plurality of holes 85 and theextension 83 is provided with a single hole so that a pin 86 passingthroughone of the holes 85 in the bracket 84 and through the hole in theextension 83 holds the rollers 80 in any desired position. vThepreferred position is that'shown in Fig. 4 in which the rollers 80 areslightly in advance of the contacting portion ofthe wheel 7 0. It hasbeen found when so arranged that the wheel 70 will follow the pathdefined by the strip 76 without difliculty. The conformation of theupper end of the floating tube 66 and of the opening 65 is such thatwhile the tube and its parts are free to reciprocate relative to theturntable 56, any rotation of the ,tube around itsvertical axis 90 willcause the turntable 56 to rotate similarly.

The torch mechanism comprises a plural ity of torches supported at thedesired points upon the cross bar 17. The bar 17 is carried by the posts18 through suitable ball and thrust bearings and may be extended to thelength desired beyond the platforms 10. Each torch 100 may comprise atube 101 which extends through a collar 102 clamped by arms 103 uponthebar 17. Suitable means (not shown) may be provided to raise or lower thetorch 100 as required and the gas or other fuel by which the flame ofthe torch is produced passes through the tube 101 to the outlet at itslower end in the usual manner.

As is clearly shown in Fig. 2 of the drawings, each platform 10 supportsa. tracer carriage 12 and a torch carriage 13 wl1ich carriages areconnected by transmission means 105 so that any movement of thecarriage/12 over the platform 10 causes a movement of the carriage 13over the platform 10 to the same extent but in the reverse direction.The transmission means 105 is'similar in many respects to that shown inmy copending below, and in the fact that the various elements operate ina horizontal plane rather than in a vertical plane.

The means 105 comprise a pair of rack bars 106 and a gear 107 with whichthe teeth on the bars mesh. The car 107 is mounted upon a vertical stubsha 108 carried by the platform over the pedestal 11 preferably in thevertical axis 31. Suitably mounted idler rolls 109 (see Fig. 6) hold theteeth of the bars 106 inmesh with the gear'l07. The outer ends of thebars 106 may be attached to the carriages 12 and 13 by the means shownin Fig. 5. Mounted upon the frame 46 of the carriage is a Z-shapedbracket 110 Whlch is adjustably secured to the frame by set I screws 111passed through slots 112. The

bracket 110 terminates in an outwardly proecting tongue 113 andprojecting from the racket above and parallel to the tongue 113 is asecond tongue 114. The end of the bar 106 enters the space between thetongues and is fixed therein by set screws 115 carried by the tongues.The tips of the screws enter depressions 116 in the upper and lowerfaces of the bar and thus permit the bar to oscillate slightly, shouldsuch movement be necessary at any time, without impairing in any respectthe operation of the transmission means.

The construction of the reproducing mechanism thus described is suchthat the movement of the tracer wheel 70 over the strip 76 caused by themoto 5.7 is transmitted by f the cross beam 15 to the carriages 12, and

through the rack bars 106 and gears 107 to the carriages 13 and thencethrough the cross bar 17 to the torches 100. The torches are thusactuated by the tracer 50 and reproduces upon the work 41 replicas ofthe. template 36.

In the transmission system shown and described, the rack bars and earsare arranged in the horizontal plane, ut they could be arranged invertical or other planes, if demechanism has been shown and described,.I

arn not limited thereto since other embodients can be made withoutdeparting fromthe spirit and scope of the invention as set forth in thefollowing claims.

I claim:

1. A reproducing machine wherein the movement of the reproducing meansis controlled by that of'a tracer relative to a template, comprising asingle tracer; a pair of 4 tracer carriages, means connecting said car?riages and supporting said tracer, a plural- 1ty of reproducing tools, apair of carriages supporting said tools and means joining each I 1.-d:.; -".gtracer carriage to a tool supporting carr age;

whereby the movement of the tracer relative";

to a template is transmitted to the'tools. M 2. A reproducing machinewherein the movement of the reproducing means is con: trolled by that ofa tracer relative to a template, comprising a' single tracer, a pair of.tracer carriages, means connecting said carriages and supportingsaidtracer, a plurality of reproducing tools, a pair of carriages, meansconnecting said carriages and supporting said tools, and means joiningeach tracer carriage to a tool-supporting carriage whereby the movementof the tracer relative to a template is transmitted to the tools.

3. A reproducing machine wherein the e movement of the reproducing meansis controlled by that of a tracer relative to a tem plate, comprising asingle tracer, apair-of platforms, a pair of tracer carriages, eachcarriage being reciprocable over a platform, means connecting saidcarriages and supporting said tracer, a plurality of reproducing tools,a pair of carriages, each carriage being reciprocable over a platform,supporting said tools and means joining the tracer carriage and thetool-supporting carriage on each platform whereby the movement of thetracer g'elntive' to the template is transmitted to the 4. A reproducingmachine wherein the movement of the reproducing means is controlled bythat of a tracer relative to a tem-.

plate, comprising a single tracer, a pair of platforms, a pair of tracercarriages, each carriage bemg reciprocable over a platform, meansconnectlng said carrlages and supporting said tracer, a plurality ofreproducing tools, a pair of carriages, each carriage being reciprocableover a platform, means connecting said carriages and supporting saidtools,

and means joining the tracer carriage and the tool-supporting carriageon each platform whereby the movement of the tracer relative to thetemplate is transmitted to the tools. 5. A reproducing machinecomprising a single tracer and means causing said tracer to moverelative to a template, tracer carriages by which said tracer issupported, a plurality of torches, torch carriages by which said torchesare supported and means joining each torch carriage to a tracer carriagewhereby the movement of the tracer is transmitted through the tracer andtorch car riages to said torches.

' 6. A reproducing machine comprising a platform, ,a tracer carriage, atorchcarriage carriages, a tracer supported by said connecting means,means connecting said torch car riages, a torch supported by said secondconnecting means, a template and a tracer actuator causing said tracerto move relative to said template whereby said torch is caused to movein unison with the tracer. Y

7. In a reproducing machine comprising a. platform having a centralpedestal, a pair of tracks and carriages reciprocable over said tracks,one carriage being at one side of the pedestal and the other'carriagebeing at the other side, means for transmitting motion from one carriageto the other and causing the carriages to move in opposite directionsrelative to the pedestal, consisting of a gear mounted to rotate in ahorizontal plane over the pedestal and a pair of rack bars which meshwith the teeth of the gear, each bar being supported at one end by acarriage.

8. In a reproducing machine comprising-a platform having a centralpedestal, a pair of tracks and carriages reciprocable over said tracks,one carriage being at one side of the pedestal and the other carriagebeing at the other side, means fortransmitting motion from one carriageto the other and causing the carriages to move in opposite directionsrelative to the pedestal, consisting of a gear mounted to rotate in ahorizontal plane over the pedestal and a pair-of rack bars which meshwith the teeth of the gear-and vertically spaced tongues on eachcarriage between which tongues oneend of a rack bar is supported.

9. In a reproducing machine comprising a platform having acentralpedestal, a pair of tracks and carriages reciprocable over saidtracks, one carriage being at one side of the pedestal and the othercarriage being at the other side, means for transmitting motion fromone'carriage to the other and causing the carriages to mov e in oppositedirections relative to the pedestal, consisting of a gear mounted torotate in a horizontal plane over the pedestal, and a pair of rack barswhich mesh with the teeth of the gear, vertically spaced tongues on eachcarriage, .between which tongues one end of a rack bar enters, and setscrews in said tongues which engage and support the rack bar whilepermitting a slight oscillation thereof. 10. In a reproducing'machinethe combination with a strip template of a tracer comprising a wheelwhich bears upon the face a ofthe template strip and roller-grindingmeans which engage the sides of the strip to insure that the wheelfollows the contour of the strip, such roller-grinding means consisting'of rollers mounted upon levers pivotally supported upon the tracer andengaging the sides of the strip in advance of the I line of contact ofthe wheel and the strip.

Signed by me at Boston, Massachusetts, this eleventh day of March, 1930.

,CARLOS KREBs.

